Problems after replacing bathroom suite

[ianmwxm]

Just finished installing a replacement bathroom suite and seem to have an array of issues with it!

Before I start I have a hot water tank in the airing cupboard and a header tank in the loft and the hot water taps are connected to this. I estimate that the tank is 2 meters above the bathroom. Cold water comes from direct feed from the mains and is quite high (no equipment to test the actual pressure!)

I have, basically, put the new suite in the same places as the previous suite but extended the pipes. Now here are the issues!!

The new sink is a mono tap and I have connected the flexi pipe connections to the existing 15mm pipes (as were connected to the old sink – but that had separate cold / hot taps). I had to extend the 15mm pipes a bit and have added a service valve before the flexi pipe. Hot water runs slower than it used to (but not a dribble) but the cold water sounds like a plane taking off when the tap is partially opened.

The old toilet was a ball valve type and the new one is a bottom fill “torbeck” type (not sure if that is the correct make or term?). It has a push button on the lid. When filling is complete it makes a loud thud. I checked the pipes and can see clips on the joists I can get to (I did add one or two additional clips) so I don’t think vibrating pipes is the problem – rather that it is a water hammer problem.

The bath taps have been changed to a mixer tap which I bought as suitable for low and high pressure systems. The cold water fill is fine but the hot water is slower than it used to be (the old taps were again separate cold / hot). Mixing the water just means I get cold water. As with all the connections I used the existing pipes but with the bath used flexi pipe to connect to the taps – 15mm for cold and 22mm for the hot. The hot flexi pipe has an integral service valve.

From my hours of looking at the world wide web I think a pressure reducing valve to the cold water mains would solve these issues but have some questions – where is best to fit one? There is no problem with any of the taps (washing machine, dishwasher, kitchen and outside) downstairs so should I fit it after the kitchen and before the bathroom or right after the stopcock? Should I fit one to each of the sink, bath and toilet? Are they ok to fit vertically? Will the reduced pressure affect my cold water fill electric shower? If it does will I need to fit a water pump to boost pressure to that (or is a power shower a better/cheaper option)? Will this pressure reducing valve stop the water hammer or should I also consider a water arrestor (or whatever it’s called. I was also reading about non-return valves for the mixer taps – would I need one of these?

I appreciate any advice anyone is able to offer

 

[aggis]

Sounds like you need a pressure reducing valve, get 1 with a guage.
Fit it after mains stop tap to protect all appliances.
It'll be set at 3bar/42psi, turn on taps & you could adjust to min 2bar/28psi.
You will always find it difficult to blend H & C, because if you have 2m taps to ceiling & 2m to bottom of tank, you've only got less than 1/2 bar 5.6psi.
Regards the taps, you need to fit non-return valves on the mixer taps

 

[Toddyplumb]

Before you do anything get your cold pressure checked .
I would hazzard a guess that most of your problems are due to fitting modern taps and flexi's that are more suited to a mains system . What is the internal bore of the 22mm flexi.
The WC , fit more clips if you can, torbecks do "slam" shut
You may be better off boosting the hot !

 

[Dannypipe]

It all points to a very common issue with monoblock brassware. Different pressures.

It's a shame you didn't take some advise before you underwent the work.

You say the hot supply runs at almost a dribble...(with the cold switched off) does it have a check valve in the flexi hose. This would mean more resistance for the hot water to overcome.

With a gravity supply check valves can result in very poor performance. It will also mean that when you turn on the high pressure cold, the hot will not flow at all. Without the check valve, the mains pressure cold would simply backfill the hot supply. Which is also no good.

Putting a Pressure reducing valve to each piece of sanitary will not only cost a fortune, but look awful.

Is there no way that you can supply the bathroom with a feed from the cold water storage tank....thus supplying balanced feeds? Oh and you could do away with the check valves.

You also say the cold sounds like a plane taking off and the WC has pipe hammer. You probably have very high pressure in your main, so a Pressure Reducing valve on the whole system might not be a bad idea. Its a five min job to check the standing pressure, I would get a plumber in to advise. Or get used to running one tap at a time!